CN1313458A

CN1313458A - Hand four stroke engine

Info

Publication number: CN1313458A
Application number: CN01111371A
Authority: CN
Inventors: 伊藤庆太; 西田隆夫
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 2000-03-14
Filing date: 2001-03-14
Publication date: 2001-09-19
Anticipated expiration: 2021-03-14
Also published as: EP1134365B1; TW562896B; US20010029921A1; CA2340576A1; AU2647201A; CN1170056C; US6505596B2; KR100376062B1; KR20010092321A; DE60117191D1; DE60117191T2; AU755108B2; EP1134365A1; CA2340576C

Abstract

In a handheld type four-cycle engine, the lubricating system includes an oil tank placed outside an engine main body, a through hole providing communication between the oil tank and a crank chamber, an oil feed pipe placed outside the engine main body and providing communication between the crank chamber and a valve operation chamber of a cylinder head, an oil return pipe placed outside the engine main body and providing communication between the valve operation chamber and the oil tank, and a one-way valve for transferring oil from the crank chamber to the valve operation chamber side via the oil feed pipe. The side walls of the engine main body can thus be made thinner and the weight of the engine main body can therefore be reduced regardless of the presence of the oil feed pipe and the oil return pipe.

Description

Hand four stroke engine

The present invention relates to a kind of main for example hand four stroke engine of the power source of cut-off machine of portable work machine that is used as, more particularly, the present invention relates to a kind of improvement of four stroke engine, this motor has: an engine main body, this engine main body have one and contain the crankcase of crankshaft room, a cylinder block that contains cylinder-bore and a cylinder head that contains suction port and relief opening; One is bearing in the crankcase and is received within bent axle in the crankshaft room; One is contained in the cylinder-bore and the piston that is connected with bent axle; Be used to open and close the suction valve and the outlet valve of suction port and relief opening, this suction valve and outlet valve are installed in the cylinder head; One can be with the rotation of bent axle start to open and close the valve operation mechanism of suction valve and outlet valve; With power output (sending an in other words) mechanism that is arranged on one of bent axle end.

The hand four stroke engine of the above-mentioned type was for example disclosing among day disclosure special permission No.10-288019.

From preventing the pollution of the environment and guarantee operator's health, that yes is useful for hand four stroke engine, because the gas of discharging is cleaner.But, because its structure is than two-cycle engine complexity, so there is the shortcoming that weight is difficult to alleviate.And weight reduction is the problem of particular importance for the operability of improving hand four stroke engine.

Yet, in the hand four stroke engine of above-mentioned patent disclosure, since be communicated with on the sidewall that the grease channel of crankshaft room and valve operation mechanism is arranged on engine main body so as lubricated be used to open and close be arranged on the interior suction valve of cylinder head and the valve operation mechanism of outlet valve, so the sidewall thickness of engine main body will increase inevitably, thereby its size is increased and be difficult to alleviate the weight of motor.

According to above-mentioned situation the present invention has been proposed.The objective of the invention is by making the engine body structure compactness that a kind of light-duty hand four stroke engine with excellent operability is provided.

According to a first aspect of the present invention, in order to achieve the above object, a kind of hand four stroke engine is provided, this motor has: an engine main body, this engine main body have one and contain the crankcase of a crankshaft room, a cylinder block that contains cylinder-bore and a cylinder head that contains suction port and relief opening; One is bearing in the crankcase and is located in bent axle in the crankshaft room; One is contained in the cylinder-bore and the piston that is connected with bent axle; Be used to open and close the suction valve and the outlet valve of suction port and relief opening, this suction valve and outlet valve are installed in the cylinder head; One can be with the rotation of bent axle start to open and close the valve operation mechanism of suction valve and outlet valve; With a power take-off mechanism on the end outside the engine main body of stretching out that is arranged on bent axle, it is characterized in that the lubrication system of this motor has: a fuel tank that is arranged on outside the engine main body and stores lubricant oil; One makes the through hole that is communicated with between fuel tank and the crankshaft room; A fuel supply line that is arranged on outside the engine main body and crankshaft room is communicated with the valve working room, above-mentioned valve working room forms in cylinder head, to hold valve operation mechanism; One also is arranged on outside the engine main body and the return tube that the valve working room is communicated with fuel tank; With a conveyer that is used for the oil in the fuel tank is sent to by crankshaft room fuel supply line.

Above-mentioned power take-off mechanism is equivalent to the centrifugal clutch described in hereinafter the embodiment, and conveyer is equivalent to the one-way valve 61 described in the embodiment.

According to first above-mentioned feature, because fuel supply line and return tube all be arranged on outside the engine main body, thus can make the sidewall attenuate of engine main body, irrelevant with being provided with of fuel supply line and return tube.Thereby make the engine body structure compactness.Reach the purpose that obviously alleviates the motor gross weight, and external fuel supply line and return tube be subjected to from the heat affecting of engine main body lessly, this just can prevent that lubricant oil is overheated.

According to a second aspect of the present invention, a kind of hand four stroke engine is provided, it is except having the first above-mentioned feature, its feature also is, a mist of oil generating mechanism that is used for producing from the oil of storing mist of oil is set in fuel tank, and the conveyer that the mist of oil that is used for producing in the fuel tank is sent to fuel supply line has a control valve unit that the malleation component of the fluctuation pressure of crankshaft room is directed to fuel supply line.

Above-mentioned control valve unit is equivalent to the hereinafter one-way valve described in the embodiment 61.

According to second above-mentioned feature, because the mist of oil that produces in the fuel tank can utilize the fluctuation pressure of crankshaft room to deliver to crankshaft room and valve working room, turn back to fuel tank 40 then, so under any working position of motor, the inside of motor all can be lubricated effectively, and do not need setting to make the special-purpose oil pump of mist of oil circuit, thereby make designs simplification.

According to a third aspect of the present invention, a kind of hand four stroke engine has been proposed, it is except having the first or second above-mentioned feature, its feature is that also fuel supply line and return tube and the band cover between the synchronous drive mechanism of surface and valve operation mechanism outside the engine main body are made integral body.

According to the 3rd above-mentioned feature, fuel supply line and return tube and band cover are made integral body and are helped reducing number of parts and improve assembly performance.

According to a fourth aspect of the present invention, a kind of hand four stroke engine has been proposed, it is except having the first and second above-mentioned features, and its feature is that also fuel supply line and return tube are flexible tubes.

According to the 4th above-mentioned feature, fuel supply line and return tube can freely be installed on any connection part by suitable bending, thereby have improved the degrees of freedom of design.

According to a fifth aspect of the present invention, a kind of hand four stroke engine has been proposed, it is except having the first above-mentioned feature, its feature also is, above-mentioned valve operation mechanism has one and is bearing in the cylinder head to open and close the camshaft of suction valve and outlet valve in rotating mode, is arranged on outside the engine main body with one and makes the no oil system synchronous drive mechanism that is connected in above-mentioned bent axle and the camshaft work; A mist of oil generating mechanism that is used for producing from the oil of storing mist of oil is set in fuel tank; And the conveyer that the mist of oil that is used for producing in the fuel tank is sent to fuel supply line has a control valve unit that the malleation component of the fluctuation pressure of crankshaft room is directed into fuel supply line.

According to the 5th above-mentioned feature, because motor is made OHC (OHC) pattern, and synchronous drive mechanism is made no oil system pattern and is placed outside the engine main body, so the Transmission Room that holds synchronous drive mechanism need be set specially on the sidewall of engine main body, therefore can make engine main body do thinlyyer and compactness, thereby can reduce the gross weight of motor significantly.Because above-mentioned control valve unit passes to valve working room one side with the malleation component of the fluctuation pressure of crankshaft room, so the mist of oil that produces in the fuel tank of engine main body one side is recycled in crankshaft room, valve working room and the fuel tank by fuel supply line and return tube, thereby the inside that is in the motor under any working position is lubricated, and do not need for the circulation of oil special-purpose oil pump to be set, thereby this helps simplified structure and reduces cost.

In addition, according to a sixth aspect of the present invention, a kind of hand four stroke engine has been proposed, it is except having second and the 5th above-mentioned feature, its feature also is, induction chamber with the top adjacency of valve working room is set in cylinder head, and return tube is connected with induction chamber, and induction chamber is connected with the valve working room by a plurality of apertures that are positioned at the different heights position.

According to the 6th above-mentioned feature, even mist of oil liquefaction also resides in the valve working room, these oil that liquefied also can for example turn back in the fuel tank by a hole suction induction chamber in the above-mentioned aperture under erectility or the topsy-turvydom at any location status of motor.Therefore, can prevent that oil from resting in the valve working room.

By below in conjunction with the detailed description of accompanying drawing to most preferred embodiment, will understand above-mentioned purpose of the present invention, other purposes, feature and advantage more, in the accompanying drawing:

Fig. 1 is an embodiment's of hand four stroke engine of the present invention in actual use a perspective view;

Fig. 2 is vertical side view of above-mentioned four stroke engine;

Fig. 3 is the enlarged view of the core component of Fig. 2;

Fig. 4 is the axial vertical cutaway view Amplified image of the cam of Fig. 3;

Fig. 5 is the sectional view along the 5-5 line of Fig. 3;

Fig. 6 is the schematic representation of the lubrication system of above-mentioned motor;

Fig. 7 is the sectional view along the 7-7 line of Fig. 3;

Fig. 8 is the sectional view along the 8-8 line of Fig. 7;

Fig. 9 is the bottom view of cowl hood;

Figure 10 is explanation motor schematic representation of the pumping action of the oil of productive set in the cylinder head when being in various working position;

Figure 11 is the sectional view that is equivalent to Fig. 7, and a kind of remodeling embodiment of fuel supply line and return tube is shown.

Below referring to the description of drawings embodiments of the invention.

As shown in Figure 1, a kind of hand four stroke engine E is fixed on for example power-actuated cut-off machine T of drive part as a kind of power source.Because the usage mode of power-actuated cut-off machine T is that its cutter C can change direction according to operating condition, so motor E also can tilt or reverse significantly, its working position is very unstable as a result.

Total structure of hand four stroke engines at first is described referring to Fig. 2～5.

Shown in Fig. 2,3 and 5, at the front and rear of the engine main body 1 of above-mentioned hand four stroke engine E a vaporizer 2 and an exhaust silencer 3 are installed respectively, and, an air cleaner 4 are installed then in the ingress of vaporizer 2.The fuel tank 5 that synthetic resin of installation is made below engine main body 1.

Engine main body 1 has: the crankcase 6 with the 6a of crankshaft room; Cylinder block 7 with a cylinder-bore 7a; With one have firing chamber 8a and the suction port 9 that is communicated with this firing chamber 8a and the cylinder head 8 of relief opening 10.Cylinder block 7 and cylinder head 8 are cast an integral body, and the crankcase 6 that casts out separately is then with the lower end of bolt to cylinder block 7.Crankcase 6 is made of the first and second half housing 6L and 6R, these two half housing 6L, and 6R is connected to each other by bolt 12.On the excircle of cylinder block 7 and cylinder head 8, make the radiating fin 38 of a large amount of cooling usefulness.

Be contained in bent axle 13 in the 6a of crankshaft room by ball bearing 14 and 14 ' be bearing in the first and second half housing 6L and the 6R, and be connected with piston 15 in the cylinder-bore 7a that packs into by connecting rod 16 in rotating mode.And, in the first and second half housing 6L and 6R, the oil seal 17 and 17 of also packing into ', this oil seal 17 and 17 ' with above-mentioned ball bearing 14 and 14 ' adjacent, and closely contact with the peripheral of bent axle 13.

The suction valve 18 and the outlet valve 19 that are used to open and close suction port 9 and relief opening 10 are separately positioned in the cylinder head 8, and parallel with the axis of cylinder-bore 7a, are screwed into a spark plug 20, make the centre area of its electrode near firing chamber 8a.

Suction valve 18 and outlet valve 19 are by the

valve spring

22 and 23 positive closings that are arranged in the valve working room 21 that cylinder head 8 forms.In valve working room 21, but the mode according to vertical vibration is bearing in the top that cylinder head 8

interior cam followers

24 and 25 are installed in suction valve 18 and outlet valve 19, the camshaft 26 that is used for opening and closing suction valves 18 and outlet valve 19 by

cam follower

24 and 25 then in rotating mode by the ball bearing 27 on the L-R wall that is positioned at valve working room 21 ' and 27 supportings, so camshaft 26 parallels with bent axle 13.The sidewall and the cylinder head 8 of the installation ball bearing 27 of valve working room 21 are made integral body, and an oil seal 28 is installed on this sidewall, closely contact with the peripheral of camshaft 26.A patchhole 29 is set, so that camshaft 26 can insert in the valve working room 21, after inserting camshaft 26, again with another ball bearing 27 ' be installed in the sidewall lid 30 of blocking patchhole 29 on another sidewall of valve working room 21.This sidewall lid 30 installs in the patchhole 29 by Sealing 31, and is connected with cylinder head 8 by bolt.

Can know from Fig. 3 and 4 and to find out that an end of camshaft 26 reaches outside the cylinder head 8 from a side of above-mentioned oil seal 28.One end of bent axle 13 also stretches out outside the crankcase 6 in the same side, a toothed drive wheel 32 has been installed on this end of bent axle 13, it is double in the toothed drive wheel 33 of drive wheel 32 that a number of teeth then is installed on the above-mentioned external part of camshaft 26, on above-mentioned two

drive wheels

32 and 33, twine a toothed synchronous belt 34, therefore, bent axle 13 can drive camshaft 26 by 1/2 reduction speed ratio.Above-mentioned camshaft 26 and synchronous drive mechanism 35 are formed the operation mechanism 53 of a valve.

Therefore, motor E is a kind of epirelief wheeled construction, and 35 of above-mentioned synchronous drive mechanisms are the no oil systems that places outside the engine main body 1.

The band cover 36 that synthetic resin is made is between engine main body 1 and synchronous drive mechanism 35, because band cover 36 is to be installed on the engine main body 1 with bolt 37, so can prevent the heat affecting synchronous drive mechanism 35 that engine main body 1 gives off.

The plastic fuel tank 40 that is mounted to the part that can cover synchronous drive mechanism 35 outer surfaces is fixed on the engine main body 1 by bolt 41, and, kick starter 42 (see figure 2)s have been installed on the outer surface of this fuel tank 40.

See Fig. 2 again, the opposite end in the end with synchronous drive mechanism 35 of bent axle 13 also reaches outside the crankcase 6, and by nut 44 flywheel 43 is installed on this end.On the internal surface of flywheel 43, integrally make many cooled

blades

45,45 ... so flywheel 43 also plays the effect of cooler.On the outer surface of flywheel 43, make a plurality of installation bases 46 (Fig. 2 illustrates one of them), centrifugal brake shoe 47 of rotatably support on each installation base 46, the clutch drum 48 of these centrifugal brake shoes 47 on being installed in transmission shaft 50 (following explanation again) constitutes a centrifugal clutch 49, when the rotating speed of bent axle 13 surpasses predetermined value, centrifugal brake shoe 47 is just owing to its action of centrifugal force is pressed on the inner circumference of clutch drum 48, thus with the output transmission of torque of bent axle 13 to transmission shaft 50.The diameter of flywheel 43 is greater than the diameter of centrifugal clutch 49.

The engine hood 51 that covers engine main body 1 and annex thereof is divided into the second half hood 51b that the first half hood 51a that are positioned at flywheel 43 1 sides and are positioned at starter 42 1 sides on the position of synchronous drive mechanism 35, this two and

half hoods

51a and 51b are fixed on the engine main body 1.Supporting sleeve 58 with the frustoconical of bent axle 13 coaxial settings is installed on above-mentioned the first half hood 51a, this supporting sleeve 58 is supporting the transmission shaft 50 that above-mentioned cutter C is rotated by rotary bearing 59, above-mentioned supporting sleeve 58 is provided with suction port 52, so cooled

blade

45,45 that can be by flywheel ... rotation and outside air is sucked in the engine hood 51.In addition, also has an end cover 54 that is installed in lower surface on engine hood 51 and the supporting sleeve 58, that be used to cover fuel tank 5.

As mentioned above, because interconnected synchronous drive mechanism 35 is arranged on outside the engine main body 1 as a no oil system between bent axle 13 and camshaft 26, so a special-purpose separation that is used to admit driving mechanism 35 need be set on the sidewall of engine main body 1, therefore the size of engine main body 1 is reduced, compact structure alleviates the gross weight of motor E greatly.

And, because the centrifugal brake shoe 47 of synchronous drive mechanism 35 and centrifugal clutch 49 is connected with the two ends of bent axle 13 respectively, and cylinder block 7 is between between them, so, the weight at bent axle 13 two ends is suitable balances, therefore the center of gravity of motor E can, can improve the operability of motor E as much as possible near the middle part of bent axle 13 in weight reduction.In addition, owing to when motor E works, act on the two ends of bent axle 13 respectively from the load of synchronous drive mechanism 35 and transmission shaft 50, so can prevent to act on the bearing 14 and 14 of bent axle 13 and supporting crankshaft 13 ' on load too concentrated, this just can improve its durability.

Moreover, owing to diameter has been installed greater than centrifugal clutch 49 and have the flywheel 43 of cooled blade 45 on the bent axle 13 between engine main body 1 and the centrifugal clutch 49, so rotation that can be by cooled blade 45 from inlet hole 52 introduce air make outside air deliver to effectively cylinder block 7 and cylinder head 8 around, and be not subjected to the interference of centrifugal clutch 49, therefore, both improved the cooling performance of motor, prevented again owing to the size that flywheel 43 increases motor E is set simultaneously.

In addition; because fuel tank 40 is installed on the engine main body 1 adjacent with synchronous drive mechanism 35; so fuel tank 40 covers the part of synchronous drive mechanism 35 at least, and protect synchronous drive mechanism 35 with the second half hood 51b of the another part that covers driving mechanism 35.In addition, because fuel tank 40 and flywheel 43 be arranged to and face one another between the engine main body between them 1, so the middle part that the center of gravity of motor E can close bent axle 13.

The lubrication system of above-mentioned motor E is described referring to Fig. 3～10 below.

As shown in Figure 3, bent axle 13 is arranged to the one end and is passed fuel tank 40, and with the inner and outer wall that is installed in fuel tank 40 on oil seal 39 and 39 ' closely contact, in bent axle 13, have through hole 55 and make within the fuel tank 40 with between the crank chamber 6a and be connected.In fuel tank 40, store lubricant oil 0, always the oil mass of storage will make the opening end of the above-mentioned through hole 55 that is positioned at fuel tank 40 inside no matter how the working position of motor E all is higher than the liquid level of oil 0.

By nut 57 disc 56 is installed on the bent axle 13 in fuel tank 40, this disc 56 has two blade 56a and 56b, these two blades extend along reciprocal radial direction from the middle part of the bent axle of installation disc 56, and along reciprocal axial direction bending.When bent axle 13 rotates and when disc 56 is rotated, no matter the working position of motor E how, at least one among two blade 56a and the 56b always broken up the oil 0 in the fuel tank 40 and made it form mist of oil.

Shown in Fig. 3,6 and 7, the 6a of crankshaft room is connected with valve working room 21 by fuel supply line 60, and an one-way valve 61 is set on fuel supply line 60, so that make oil only along flowing to the direction of valve working room 21 from the 6a of crankshaft room.Above-mentioned fuel supply line 60 is made integral body along a side of above-mentioned band cover 36 with it, the lower end of fuel supply line 60 then forms in valve chamber 62.Make integral body from the oil inlet pipe 63 that the valve chamber 62 at the rear portion of band cover 36 stretches out with band cover 36, this oil inlet pipe 63 is packed into by Sealing 65 in the attachment hole 64 of crankcase 6 bottoms, so oil inlet pipe 63 is connected with the 6a of crankshaft room.Above-mentioned one-way valve 61 is arranged in the valve chamber 62, and only 62 direction flows along oil inlet pipe 63 to valve chamber so that make oil.In the present embodiment, above-mentioned one-way valve 61 is a kind of leaf valves.

The oil exit pipe 66 that stretches out from the upper end of being with the fuel supply line 60 that covers 36 rear portions is made an integral body with band cover 36, and this oil exit pipe 66 is fit in the attachment hole 67 of cylinder head 8 sides, so it is connected with valve working room 21.

Therefore, the valve working room 21 that is communicated with fuel supply line 60 by be arranged in the bent axle 26 and have transverse holes 68a and vertically gas-liquid split tunnel 68 and the sidewall cover 30 interior ventilation chamber 69 of hole 68b be connected, above-mentioned ventilation chamber 69 is connected with the inside of above-mentioned air cleaner 4 by breathing pipe 70.

Shown in Fig. 4 and 9, the head cover 71 that is used to cover the opened upper surface of valve working room 21 is fixed to cylinder head 8 by Sealing 72.In head cover 71, form one by a plurality of

apertures

73,73 ... the induction chamber 74 that is communicated with valve working room 21.This induction chamber 74 is pancake along the upper surface of valve working room 21, and on 4 positions of its bottom, 4

apertures

73,73 are set ...Apneusis tracheae 75 and short sucking pipe 76 are made an integral body in central position and its bottom of induction chamber 74, and it is at regular intervals on the direction of edge between long and short sucking

pipe

75 and 76 perpendicular to the axis of camshaft 26, so that stretch into 21 inside, valve working room, in sucking

pipe

75,76, also be provided with

aperture

73 and 73.

Shown in Fig. 6～8, induction chamber 74 also is connected with fuel tank 40 inside by return tube 78.Above-mentioned return tube 78 is made integral body at the edge of a side upper edge band cover 36 relative with fuel supply line 60 1 sides with it, make an integral body at the oil inlet pipe 79 that protrude from the upper end of return tube 78 at the rear portion of band cover 36 with band cover 36, this oil inlet pipe 79 also is connected with the oil exit pipe 80 of formation in the head cover 71 by connector 81, so oil inlet pipe 79 is connected with induction chamber 74.

In addition, the oil exit pipe 82 that stretches out from the lower end of return tube 78 at the rear portion of band cover 36 is made integral body with band cover 36, and this oil exit pipe 82 is packed into and is arranged in the spill port 83 in the fuel tank 40, so, be connected within oil exit pipe 82 and the fuel tank 40.The opening end of spill port 83 is positioned near the middle part of fuel tank 40, so no matter the working position of motor E how, above-mentioned opening end all is higher than the liquid levels of oil in the fuel tank 40.

Stretching out of bent axle 13 follower that is driven by above-mentioned kick starter 42 has been installed on the front end outside the fuel tank 40.

In the working procedure of motor E, owing to rotating the lubricant oil 0 that disc 56 is broken up in the fuel tank 40, bent axle 13 produces mist of oil, when the pressure of the 6a of crankshaft room reduces owing to the ascending motion of piston 15, the mist of oil that is produced just enters the 6a of crankshaft room by through hole 55, thereby bent axle 13 and piston 15 are lubricated.When the pressure of the 6a of crankshaft room owing to the decline of piston 15 is moved when improving, one-way valve 61 is just opened, the result, the gas leakage that above-mentioned mist of oil produces in the 6a of crankshaft room rises in the fuel supply line 60, and deliver in the valve working room 21, this just makes camshaft 26,

cam follower

24 and 25 etc. be lubricated.

When the mist of oil in the valve working room 21 and gas leakage enter gas-liquid split tunnel 68 in the bent axle 26 that is rotating, because action of centrifugal force, just in this passage 68, make gas and liquor separation, the oil that has liquefied turns back to valve working room 21 by the transverse holes 68a of gas-liquid split tunnel 68, and above-mentioned gas leakage then enters among the motor E by ventilation chamber 69, breathing pipe 70 and air cleaner 4 in the suction stroke process of motor E in regular turn.

Because valve working room 21 is connected with the inside of air cleaner 4 by gas-liquid split tunnel 68, ventilation chamber 69 and breathing pipe 70 as mentioned above, so the pressure in the valve working room 21 can keep atmospheric pressure or be lower than atmospheric pressure slightly.

On the other hand, the pressure average out to negative value of the 6a of crankshaft room is because have only the positive pressure component of fluctuation pressure just to discharge by one-way valve 61.Above-mentioned negative pressure reaches fuel tank 40 by through hole 55, and further passes to induction chamber 74 by return tube 78.Therefore, pressure in the induction chamber 74 is lower than the pressure in the valve working room 21, and, pressure in the fuel tank 40 is lower than induction chamber 74 internal pressures, the result, pressure just by sucking

pipe

75 and 76 and

aperture

73,73 ... pass to induction chamber 74 from valve working room 21, pass to fuel tank 40 by return tube 78 again, meanwhile, by sucking

pipe

75 and 76 and

aperture

73,73 ... with mist of oil in the valve working room 21 and the liquefaction oil suction induction chamber 74 that rests in the valve working room 21, flow back to fuel tank 40 by return tube 78 again.

As mentioned above, owing on 4 positions of induction chamber 74 bottoms, be provided with 4

apertures

73,73, and stretching into the length that a spacing is arranged along the direction perpendicular to the axis of camshaft 26 to each other of valve working room 21 from above-mentioned bottom center position, also be provided with

aperture

73 and 73 in the short sucking

pipe

74 and 75, so, no matter the working position of motor E is (erectility for example shown in Figure 10 (A) how, state (B) is tilted to the left, state (C) is tilted to the right, left side configuration state (D), right configuration state (E) and topsy-turvydom (F)), 6

apertures

73,73, in always have an immersion to be stored in the oil in the valve working room 21, and can be with in the oily suction induction chamber 74.

Owing to utilized the fluctuation pressure of crank chamber 6a and the function of one-way valve 61, the mist of oil that is produced in the fuel tank 40 is infeeded in the 6a of crankshaft room and valve working room 21 of overhead cam shaft type four stroke engine E, turn back to fuel tank 40 then, so, no matter the working position of motor E how, the inside of motor E all can be lubricated reliably by mist of oil, and do not need to be provided with to be specifically designed to make mist of oil circuit pump, but so simplified structure.

The fuel tank 40 made of synthetic resin but also make the fuel supply line 60 that is communicated with between the 6a of crankshaft room and the valve working room 21 and the return tube 78 that is communicated with between induction chamber 74 and the fuel tank 40 all is placed in outside the engine main body 1 not only, so the size decreases that can successfully make engine main body 1 is and more compact, this just can significantly alleviate the weight of motor E.Especially, because external fuel supply line 60 and all less influence that is subjected to from the heat of engine main body of return tube 78, so can prevent that lubricant oil 0 is overheated.In addition, because fuel supply line 60 and return tube 78 are all made integral body with band cover 36, this just helps to reduce number of parts, improves assembly performance.

Figure 11 illustrates the remodeling embodiment of fuel supply line 60 and return tube 78, and in this embodiment, fuel supply line 60 and return tube 78 are for example pipes of making of rubber of flexible material, and separate with band cover 36.Because the miscellaneous part in the present embodiment is all identical with parts in the above embodiments, thus in the drawings accordingly parts represent with identical label, and no longer illustrated.

According to this remodeling embodiment, can they freely be installed on any connection part by suitably crooked fuel supply line 60 and return tube 78, this has just improved the degrees of freedom of design.

The present invention is not limited to the above embodiments, but can under the situation of spirit and scope of the invention, retrofit in every way, for example, a kind of spherical valve that is connected with bent axle 13 can be set to substitute above-mentioned one-way valve 61, when piston 15 descends, spherical valve start and open fuel supply line 60, and when piston 15 rose, spherical valve was then blocked fuel supply line 60.

Claims

1. hand four stroke engine, it has:

An engine main body, this engine main body have one and contain the crankcase of crankshaft room, a cylinder block that contains cylinder-bore and a cylinder head that is provided with suction port and relief opening;

One is bearing in the crankcase and is received within bent axle in the crankshaft room;

One is installed in the above-mentioned cylinder-bore and the piston that is connected with above-mentioned bent axle;

Be used to open and close the suction valve and the outlet valve of above-mentioned suction port and relief opening, this suction valve and outlet valve are installed in the above-mentioned cylinder head;

One can be with the rotation of bent axle start to open the valve operation mechanism of above-mentioned suction valve and outlet valve; With

Power take-off mechanism on end of stretching out engine main body outside that is arranged on bent axle;

Wherein, above-mentioned motor also has lubrication system, and this lubrication system comprises:

One is placed in the fuel tank that the engine main body outside is used to store lubricant oil;

One makes the through hole that is connected between fuel tank and the crankshaft room;

One places and makes the fuel supply line that is connected between crankshaft room and the valve working room outside the engine main body, and above-mentioned valve working room forms in cylinder head, so that receive valve operation mechanism;

One also is to place outside the engine main body and make the return tube that is communicated with between valve working room and the fuel tank; With

A conveyer that makes the interior oil of fuel tank deliver to fuel supply line by crankshaft room.

2. according to the hand four stroke engine of claim 1, it is characterized in that, a mist of oil generating mechanism that is used for producing from the oil of storing mist of oil is set in fuel tank, and the above-mentioned mist of oil with producing in the fuel tank is sent to conveyer in the fuel supply line and has a control valve unit that is used for the malleation component of the fluctuation pressure of crankshaft room is directed to fuel supply line.

3. according to the hand four stroke engine of claim 1 or 2, it is characterized in that above-mentioned fuel supply line and return tube and the band cover between the synchronous drive mechanism of the outer surface of engine main body and valve operation mechanism are made integral body.

4. according to the hand four stroke engine of claim 1 or 2, it is characterized in that above-mentioned fuel supply line and return tube are flexible pipes.

5. according to the hand four stroke engine of claim 1, it is characterized in that, above-mentioned valve operation mechanism has one and is bearing in the cylinder head to open and close the camshaft of suction valve and outlet valve in rotating mode, be arranged on outside the engine main body with one and make the no oil system synchronous drive mechanism that is connected in above-mentioned bent axle and the above-mentioned camshaft work, be provided with one and produce the mist of oil generating mechanism of mist of oil from the oil stored in fuel tank, the conveyer that the above-mentioned mist of oil with producing in the fuel tank is sent to fuel supply line has a control valve unit that is used for the malleation component of the fluctuation pressure of crankshaft room is directed to fuel supply line.

6. according to the hand four stroke engine of claim 2 or 5, it is characterized in that, an induction chamber that is connected with the top of valve working room is set in cylinder head, thereby return tube is connected with induction chamber, and above-mentioned induction chamber is connected with the valve working room by a plurality of apertures that are arranged on the different heights.